I would like to make a cross section like this (only the hatched part)
using bézier curves/circles, to then use in a screw modifier and make a drill bit.
I initially thought I could use a Boolean operation (difference) with a set of Bézier circles like this:
but for Béziers there seem to be no Boolean modifiers. When I convert them to mesh (using Alt-C), the Boolean modifier becomes available but "difference" has no effect.
Apart from manually shaping a curve (by dragging nodes and handles), is there another, more "mathematical" way, of achieving the result?